The addition of Titleist's Pro V1 and Pro V1x "split arrow" golf balls to the USGA's conforming golf ball is a strong signal that updated versions are ready for the company's seeding and validation process that typically occurs before a product is released to the masses.
The "split arrow" naming isn't a new version of V1 or V1x, but rather how the USGA differentiates the forthcoming 2027 offerings from previous versions. Titleist didn't mention any testing occurring at the Biltmore Championship, so we'll have to wait and see which event they tap for the first round of tournament testing.